1. Field of the Invention
The present invention relates to a four-way slide switch used for remote controls for various electronic appliances (such as TV sets and video equipment), portable telephones, and others.
2. Description of the Prior Art
Recently, multidirectional switches, which can arbitrarily select a large number of circuits, have been used for remote controls for various electronic appliances (such as TV sets and video equipment), portable telephones, and others. Particularly, four-way switches of the type have been broadly used, by which switching operations are performed by tilting a manipulation member in four (back, forth, right and left) directions and vertically descending it at the center (neutral) position.
FIG. 19 shows a conventional four-way switch. The four-way switch includes a stationary contact Exe2x80x2, COMxe2x80x2 formed on the center surface of the base substrate of an insulating case 100, stationary contacts Axe2x80x2 and Exe2x80x2, Bxe2x80x2 and Exe2x80x2, Cxe2x80x2 and Exe2x80x2, and D7 and Exe2x80x2 (where E is a common contact) formed around of the center stationary contact and arranged at equal angle intervals in four directions (1), (2), (3) and (4), push-type switching means Sxe2x80x2 (center), Sxe2x80x2 1, Sxe2x80x2 2, Sxe2x80x2 3, and Sxe2x80x2 4 each formed of a diaphragm-type contact spring disc 111 placed to each stationary switch, and tilting members (not shown) such as discs, each having a depressing member mounted upward so as to confront each switching means.
When the tilting member is depressed downward from the center (neutral) position, the depressing member deforms the contact spring disc 111 of the switch means Sxe2x80x2 to bring the stationary contact Exe2x80x2, COMxe2x80x2 to an electrically conductive state (the switch is turned on). When the depression is released, the tilting member returns to its original position by the restoring force of the contact spring disc 111 (the switch is turned off).
When the tilting member is tilted from the center position toward one of the four directions (1), (2), (3) and (4), the corresponding depressing member deforms the contact spring disc 111 of one of switch means Sxe2x80x2 1, Sxe2x80x2 2, Sxe2x80x2 3 and Sxe2x80x2 4. Thus, stationary contacts, Axe2x80x2 and Exe2x80x2, Bxe2x80x2 and Exe2x80x2, Cxe2x80x2 and Exe2x80x2, or Dxe2x80x2 and Exe2x80x2 are brought to an electrical conduction state (to turn on the switch). When the depression is released, the tilting member returns to its original position by the restoring force of the contact spring disc (to turn off the switch).
As described above, the conventional four-way switch uses five diaphragm-type contact spring discs, which are disposed at the center and in four directions. However, minute diaphragm-type contact spring discs with high precision are required and are expensive. Using five diaphragm-type contact spring discs leads to an increased cost of the switch. (For example, the case for a four-way switch has an external size of 10 mm in depthxc3x9710 mm in widthxc3x972 mm in height and the contact spring disc has a diameter of 3 mm to 4 mm).
Moreover, it is difficult to arrange the contact spring discs at the center and at positions in four directions accurately and stably. The contact spring disc is easily displaced by external shock.
When the tilting member is erroneously depressed in a slant direction, the center switch means may not be turned on accurately. Meanwhile, the switch means to be operated by only the oblique movement may be erroneously turned on.
The present invention is made to solve the above-mentioned problems.
An object of the invention is to provide an improved four-way switch wherein a closed circuit is formed by cooperatively tilting a control knob and a tiltable member in an intended direction or by depressing only the control knob, thus selectively providing electrical signals.
According to the present invention, the contact spring disc, which raises problems in cost and in switch design, is used only for the center switch means, which is easily mounted and maintained. Strip-like contact spring pieces, which can be designed and fabricated easily and at low cost, are used for the four-ways switch means.
Moreover, the tiltable member, having contact spring units extended in four directions therefrom, and the control knob are disposed separately. The control knob is vertically engaged slidably into the square hole of the tiltable member. The protruded portions of the control knob are detachably engaged into the recessed portions of the tiltable member. When the center switch means is operated, only the control knob descends vertically and then restores. When the four-way switch means is operated, the tiltable member and the control knob operate in a linkage mode. This switch structure can eliminate an erroneous operation, thus effectively solving the problems in the prior art.
According to an aspect of the present invention, a four-way switch comprises a tiltable body formed of an insulating plate having a square opening in the center thereof, the tiltable body having recessed portions on the lower inner side in the square opening; a contact resilient unit formed of a base portion of a conductive resilient plate from which return spring pieces and contact spring pieces are protruded out in parallel; a tiltable member in which contact resilient units are embedded, the tiltable member having four peripheral sides each from which a set of a return spring piece and contact spring pieces is protruded out, the center of the opening of the tiltable body and the center of each of four sides of the square opening being aligned with the center of the base portion of each contact resilient unit; a control knob having a shaft, protruded portions, a knob, and a bulge, the shaft being slidably inserted into the square opening of the tiltable member, the protruded portions being formed at the lower end of the shaft and being detachably engaged in the recessed portions of the tiltable body, the knob extending upward from the shaft, the bulge being protruded from the center of the lower end of the shaft; a contact spring disc inserted into the center of a case, the fringe of the contact spring disc being disposed so as to contact with stationary contacts formed on the upper surface of the case, the center portion of the contact spring disc confronting a center stationary contact formed on the upper surface of the case; wherein the shaft of the control knob is inserted into the opening in the tiltable member; the structure in which the protruded portions and the recessed portions are engaged to each other is disposed inside the case; the center of the bulge of the control knob is aligned with the center of the upper surface of the contact spring disc; the return spring pieces are respectively placed on spring rests formed inside the case; and the contact spring pieces are respectively disposed over stationary contacts on the upper surface so as to be spaced away from each other; and a cover plate for covering the upper opening of the case, the cover plate having a center hole therein, the knob of the control knob protruding upward from the center hole of the cover plate, the cover plate pressing the inner surface around the center hole against the peripheral portion of the tiltable body, with the return spring pieces biased.
When the knob of the control knob is tilted in an intended direction, the control knob and the tiltable member are tilted together against the restoring force of the return spring pieces of a corresponding resilient unit so that the ends of the contact spring pieces are electrically contacted with corresponding stationary contacts disposed on the upper surface of the base substrate of the case.
When tilt of the knob is released, the knob returns to its original position by a restoring force of the return spring pieces.
When the knob of the control knob is depressed, only the control knob slidably descends into the square opening of the tiltable member, so that the bulge of the control knob depresses the center portion of the contact spring disc and thus electrically connects the center portion thereof to the center stationary contact.
When the knob is released from its depression, the knob returns to its original position by a restoring force of the contact spring disc.